The present invention relates to an arrangement for exchange of empty bobbins with full filament-carrying bobbins in a bobbin creel which cooperates with a textile machine for processing filaments (yarns or threads) from the bobbin creel.
Bobbin creels are intended for delivery of filaments from bobbins to a filament-processing textile machine, e.g., a beamer, and include several rows of creels in parallel relationship. Normally, each creel row has delivery positions for the bobbins on both sides. For example, the creel row may have ninety delivery positions in the horizontal in side-by-side disposition and six positions in vertical superimposed disposition. Common bobbin creels have three creel rows so that a total of 3240 delivery positions for the bobbins are provided.
The bobbins are readied, e.g., in boxes, for use in the creel. A box contains typically thirty bobbins. Heretofore, an operator oftentimes takes full bobbins from the box in the area of the creel and transfers them manually to the various delivery positions. Bobbins of a diameter of about 240 mm can have a weight of 9 to 10 kg so that the physical stress on the operator is significant when carrying out the transfer of full bobbins. In cases that involve even greater bobbin diameters and therefore greater weights, the physical stress may become extreme enough to violate worker""s protection rules.
When further considering that the so-called doffing time, i.e. the time spent for changing a bobbin including shutdown period of the textile machine, time for cutting the yarns, removing empty bobbins, positioning new bobbins, connecting the yarns, and re-starting of the textile machine, is about 30 hours, which means about 33 seconds per bobbin in a creel of 3240 bobbins, and that the actual bobbin operation is about 24 hours for a bobbin diameter of about 240 mm, it is evident that the overall operation is not viable in an economic sense.
European Pat. No. EP 0 678 469 A2 describes an arrangement with a feed device for bobbin creels having modules for executing particular functions. The modules are all placed at ground level and travel at that level. The feed device includes an endless conveyor which extends in a vertical direction and is trained about pulleys which rotate about horizontal axes. The endless conveyor is provided with transport spikes extending transversely to the conveyor and intended for receiving individual yarn-carrying bobbins which are loaded by hand. After placement of the bobbins onto a transport spike, the individual bobbins are moved by the endless conveyor until all transport spikes have received yarn-carrying bobbins. Subsequently, the feed device travels transversely to the creel until positioned in front of a bobbin carriage which is provided with a spike carrier for carriage spikes. The spike carrier is so configured as to allow a limited travel in a vertical direction in order to compensate differences in height between a carriage spike, a transport spike and a creel spike in the respectively lowermost positions.
A transfer of the yarn-carrying bobbins from the feed device to the spikes of the bobbin carriage is implemented in a region which is at a significant distance away from a bobbin transfer position between the carriage and the creel. Therefore, the demand on space for the feed device and the carriage is significant in horizontal plane in circumferential direction of the creel. In addition, the transport spikes of the endless conveyor must be loaded with full yarn-carrying bobbins by hand in the area of the feed device. As a result, there is added need for space for the worker as well as transport of full bobbins. This drawback in conjunction with the space demand is further compounded when considering that typical creel assemblies have several rows of creels in side-by-side disposition and when considering the length of each creel row. Therefore, a bobbin carriage has to be moved into a front area of a creel when being loaded with full bobbins.
German Pat. No. DE 91 11 871 U1 discloses an extremely complicated overhead carriage which is made of many components. The carriage is suspended from rails and travels in a direction perpendicular to the transport direction of a delivery conveyor. Rotatably connected to the carriage via a vertical shaft is a rail for guiding a running gear having a mounting for spikes projecting out from both sides. These spikes cooperate with spikes of an intermediate conveyor having a revolving belt.
German Pat. No. DE 91 09 079 U1 discloses an apparatus for supplying a bobbin carriage of a creel.
It would be desirable and advantageous to provide an improved arrangement for exchange of empty bobbins with full bobbins in a bobbin creel, which obviates prior art shortcomings and which is much less strenuous to an operator while still significantly enhancing the overall efficiency.
According to one aspect of the present invention, an arrangement for exchanging empty bobbins with full bobbins includes a creel assembly including rows of creels which have lateral delivery positions configured for holding filament-carrying bobbins, a textile machine receiving filament from the creel assembly, at least one bobbin carrier disposed in overhead relationship to the creel assembly and having several transport positions for bobbins, a guide system having a guide rail for travel of the bobbin carrier in suspended disposition along a travel path, a bobbin transfer assembly having a moveable transfer unit disposed on one side of the creel row and a moveable transfer unit disposed on the other side of the creel row, each of the transfer units including an upright moveable along the creel row and at least one support moveable along the upright and having receptacles for the bobbins, wherein the receptacles are moveable in a horizontal direction with respect to the support, wherein the delivery positions in the creel row in neighboring disposition to the transfer unit are provided at a number and at a distance which corresponds to a number of and a vertical distance of the transport positions on the bobbin carrier, a feed station disposed in the travel path for supply of full bobbins, a storage station disposed in the travel path for storing carrier bobbins loaded with full bobbins, and a cleaning station for cleaning empty bobbins.
The present invention resolves prior art problems by the provision of at least one bobbin carrier configured in dependence on the size of the respective bobbin creel and arranged in the area of the creel above a creel row and suspended from a guide rail for travel along a predetermined path. Oscillating movements are hereby eliminated. The exact positioning of the carrier above a creel row is significantly enhanced.
The use of such a bobbin carrier allows transport of full bobbins to the delivery positions of a creel row and removal of empty bobbins, i.e., bobbin cases, from the creel row for transfer to a renewed bobbin production, i.e., loading the empty bobbin with filaments. The exchange of empty bobbins with full bobbins can be realized by initially transporting the bobbin cases away by means of a carrier and subsequently transferring full bobbins from another, respectively loaded, carrier onto the empty delivery positions. Of course, it is also conceivable, to move a bobbin carrier with an array of empty transport positions onto the bobbin cases and subsequent placement of full bobbins from this bobbin carrier onto the empty delivery positions of a creel row. As a consequence, parallel, overlapping or sequential exchange operations can be carried out.
The transfer of the bobbin cases from the delivery positions onto the transport positions of a bobbin carrier, or the transfer of full bobbins from the transport positions of a carrier onto the delivery positions, is implemented by the transfer unit which can be operated by hand or automatically, e.g. in response to a memory-programmable control system. In case of an automatic control, the transfer unit and/or a bobbin carrier and/or a creel row may include sensors to ensure that the receptacles of the transfer devices are positioned in a precise location relative to the delivery positions of one creel row, on the one hand, and the transport positions of a bobbin carrier, on the other hand.
The support of a transfer device may, for example, be realized by a strip that is guided by the upright. The receptacles may be made of pins that are suited to the inner diameter of the bobbin cases. Shift of a support may be implemented pneumatically, electrically or also hydraulically.
An upright may be provided with a support on only one side or on both opposite sides of the upright. Which configuration is selected depends on whether the transfer unit is positioned only laterally of a bobbin creel or positioned between two neighboring creel rows. A reliable transfer of bobbin cases from the delivery positions onto the receptacles and from the receptacles onto the transport positions of a bobbin carrier, or a reliable transfer of full bobbins from a bobbin carrier via a transfer unit onto a creel row, are ensured by the horizontal travel of the receptacles with respect to the support. This horizontal movement can also be implemented pneumatically, electrically or hydraulically.
Each bobbin carrier is integrated in a conveyor system which has incorporated therein also the feed station for full bobbins, the storage station for bobbin carriers loaded with full bobbins, and the cleaning station for the bobbin cases. Such a conveyor system with rails represents an automatic circulation system in which full bobbins from the feed station are transported by the bobbin carriers toward the creel and there by at least one transfer unit from the bobbin carrier onto the delivery positions of the creel, whereas bobbin cases are transferred from the delivery positions onto the transport positions of the bobbin carrier. The bobbin cases are then cleaned in the cleaning station. Of course, the movement of the carriers may also be implemented by hand or semi-automatically.
The feed station may include a manually-operated handling device by which full bobbins can easily be withdrawn from a box and transferred onto a transport station of a bobbin carrier. The bobbin carrier loaded with full bobbins is then moved to a storage station and, if need be, subsequently moved from the storage station to the creel. Empty boxes are transported to a production site for bobbins.
The so-called doffing time, i.e. the period for exchange of an empty bobbin (bobbin case) with a full bobbin, including shutdown period of the textile machine, time for cutting the yarns, removing empty bobbins, positioning new bobbins, connecting the filaments and re-starting of the textile machine, can now be significantly reduced. As a consequence, the ratio between doffing time to bobbin running time is much improved and this improvement is accompanied by an absence of any physical stress for the worker. The bobbin cases as well as in particular the full bobbins are supported by the transfer unit. Thus, the weight of the bobbins, in particular of the full bobbins is now of secondary consideration. Bobbins of great diameter may be used, even further improving the relation between the doffing time to the bobbin running time.
The number of bobbin carriers is dependent on the number of delivery positions in the creel. In this way, a sufficient number of carriers with empty and full transport positions can be made available at all times. As the bobbin carrier is in overhead disposition above a creel row, the filaments are not obstructed when pulled off the delivery position onto the textile machine.
When providing a bobbin carrier with a number of transport positions in correspondence to the number of delivery positions, e.g. six superimposed delivery positions, the doffing time can be reduced to a cycle of about 1.5 to 2 min in case of 36 bobbins on each side of the creel through simultaneous removal and attachment of six bobbins by a transfer unit. Assuming a creel having three creel rows with a total of 3,240 delivery positions, the doffing time is about 135 to 180 min. Considered in this calculation is the time of stoppage of the textile machine, cutting of e.g. threads by the workers and their attachment as well as renewed tying of the threads of the full bobbins as well as starting of the textile machine.
According to another feature of the present invention, the number and distance of the receptacles in superimposed disposition on the transfer unit corresponds to the number and vertical distance of the delivery positions or transport positions. In this way, the exchange of empty bobbins with full bobbins is further accelerated.
According to another feature of the present invention, the bobbin carrier may include a framework with several vertical posts having upper and lower ends, with the upper ends of the posts being interconnected by an upper locking bar and the lower ends of the posts being interconnected by a lower locking bar. The posts and locking bars may be made of hollow square sections. Extending transversely from the posts, the bobbin carrier may include pins arranged in pairs and staggered by 180xc2x0 to form the transport stations. The pins have longitudinal axes which may extend horizontally or may slightly slant upwards from the posts.
According to another feature of the present invention, the bobbin carrier may include support rollers positioned in an area above the upper bar and rotatable about horizontal axes. Suitably, two pairs of rollers may be disposed behind one another in proximity of each end of the upper locking bar. The roller pairs may be rotatable about a vertical axis so as to be able to negotiate curved sections of the travel path of the guide. The guide may have a U-shaped cross section which is open downwards and is formed with inwardly turned confronting flanges having inside surfaces for defining running surfaces for the support rollers.
According to another feature of the present invention, the bobbin carrier may include guide rollers positioned in an area below the lower bar and rotatable about vertical axes. The guide rollers roll along inner sidewalls of a downwardly open U-shaped rail which is secured above each creel row.
According to another feature of the present invention, the lower locking bar of the bobbin carrier may include cross members which are supported on running rollers, so as to allow a movement of the bobbin carrier on the ground. Suitably, the running rollers are mounted to the cross members for rotation about vertical axes.
According to another feature of the present invention, the upright is guided on both ends to move in a predetermined path. This can be implemented by securing the upright on a base plate which is supported on rollers rotatable about horizontal axes and having lateral collars for encompassing floor rails. Disposed on the upper end of the upright may be a guide roller which is rotatable about a vertical axis and projects into an downwardly open U-shaped rail.
The longitudinal movement of the upright may be realized manually, pneumatically, electrically or hydraulically.
According to another feature of the present invention, the arrangement may further include a production unit for making full bobbins, wherein the feed station is positioned upstream of the production unit in the travel path. Thus, there is no need to transfer full bobbins from boxes onto the transport positions of a bobbin carrier but the full bobbins can be directly transferred from the production unit onto the transport positions of a bobbin carrier. Hereby, the bobbin-making production unit may be provided, e.g., with lateral longitudinal conveyors and at least one transverse conveyor at one end for transporting the full bobbins to the feed station.